In AC type G, R and AF pumps the glass bowl is not there for filtration... although a brass screen is commonly installed.
The glass dome is a very important part of the pump.. called the pulsator. It increases the pumps ability to move fuel by up to 50%. The small air pocket at the top of the pulsator is compress on the 'suction' stroke. When the intake valve shuts the only thing left to push the fuel is that compressed air pocket.
Almost all 2 valve pumps will have a pulsator either as part of a sediment trap or as a discrete part.
Last edited by pfarber; 08/25/2013 4:14 PM.
